You can do this by using ffmpeg and ffserver.
You first have to set a ffserver saying
that you get a flux and making it available on a socket. see http://ffmpeg.org/ffserver-doc.html
for more information. (on linux: ffserver -f test.conf)
The sole problem is to configure the ffserver (the .conf file). But the documentation is quite ok and you have an example in the default .conf file.
Then create your content with ffmpeg by sending a webcam flux for example to the socket
(on linux: ffmpeg -r 15 -s 320x240 -fvideo4lilnux2 -i /dev/video0 http://192.168.0.54:8090/feed1.ffm)
Then you put this code to your air apps:
<s:VideoDisplay id="display" autoPlay="true" width="100%" height="100%"
<s:TextInput id="txt" width="100%" enter="launchChat()"/>
It will display on the videodisplay the flux of your webcam.
By setting the IPadress, and redirect your ports, you can even use that all over the world.
I never did that, but there is a section that explain how to setup the ffmpeg tools on windows at this adress:
Installing the tools will be the most difficult part but as it is just some c soft, it can't be that hard.